Geometry, can someone help asappp

Question

diameter of a circle has endpoints at (-7,7) and (1,11) which of the following would be the coordinates of the center of the circle?

1) (-15,3 )

2) (9,15)

3) (-3,9)

4) (-6,18)

Answer 1

3) take the average of the two points to get ((-7+1)/2 , (7+11)/2) = (-3,9)